Two-stage, solid propellant, fin stabilized, unguided Russian sounding rocket, fired in greater numbers than any other. At least 6,640 of all models were fired to the edge of space before the vehicle was discontinued in 1990. 4,908 of the basic M-100 model were fired from 1957-07-11 to 1983-09-28.

The M-100 is said to have begun testing in 1953, using propellant with a specific impulse of only 150 seconds. The rocket was used to make basic weather soundings on a world-wide basis. A typical flight consists of launch to 90 km altitude, following by the descent of the nosecone under a parachute over a period of 50 minutes. During the descent the payload radioed temperature, pressure, and density data. Below 50 km radar could be used to track the nose cone and determine winds aloft. In the 1970's the M-100B was cross calibrated by firing it simultaneously with American Super Loki-Dart, British Skua, and French Super-Arcas rockets. This allowed it to be integrated into the World Meteorological Rocket Network.

While the M-100 has been equipped with non-standard payloads, it was used in such numbers over such a long period that the data from the series was used to determine long-term climate trends (a steady drop in temperature of 0.3 to 1.0 deg C per year at an altitude of 80 km).

When the Soviet Union collapse, funding for state scientific work evaporated. Launches of the M-100 abruptly ended.